Heaters for liquids



H MANSFIELD HEATERS FOR LIQUIDS 3 Sheets-Sheet 1 Filed July 5, 1968INVENTOR HENRY MANSFIELD 7 BY W444 ATTORNEY Feb. 17, 19 70 MANSFIELDnm'rnns FOR LIQUIDS 3 Sheets-Sheet. 2

Filed my 5, 195a mm. Eu MM E INVENTOR HENRY MANSFIELD BY W I A ORNEY H.MANSFIELD HEATERS FUR LIQUIDS Feb. 17,1970

. 3 Sheets-Sheet 3 Filed July 5. 1968 mvmron HENRY MANSFIELD w 2' v I IW TTORNEY United States Patent 3,495,575 HEATERS FOR LIQUIDS HenryMansfield, Greenhurst, St. Lurkers Road, Dosely, Dawley, Shropshire,England Filed July 5, 1968, Ser. No. 742,921 Claims priority,application Great Britain, July 7, 1967, 31,320/ 67 Int. Cl. F22b 7/12US. Cl. 122-149 3 Claims ABSTRACT OF THE DISCLOSURE The liquid heater isparticularly suitable as a water heater for installations such aslaundries and comprises a cylindrical glass fibre tank having at leastone stainless steel end plate at one end for the location of immersiontubes, ducts and heating and control means.

The present invention concerns improvements in or relating to liquidheaters and specifically to water heaters for use in la-undries andlaundrettes.

For washing purposes in lanndries and laundrettes it is essential tohave a ready supply of clean, hot water. Normally this is achieved bythe provision of a heater and a storage tank which prove cumbersome,space consuming and ineflicient.

According to the present invention a liquid heater comprises asubstantially cylindrical, closed glass fibre tank for containing liquidand having a stainless steel end plate secured at at least one end forthe location of immersion tubes, ducts and heating and control means.

The heating means may be one or more immersion tubes extending into thetank for example for receiving combustion products from an oil or gasfired burner, in which case the tube or tubes terminate in a fluelocated on the end plate and tubes may be interconnected with an exhaustduct. Safety devices such as pilot lights, flame failure controls andlow pressure cut-outs and pressure governors may be provided and theoperation of the burners be controlled by a thermostat. Alternativelythe heating means may be electricity or waste heat. A liquid pressuresafety valve may also be incorporated.

One or each of the ends of the tank may be provided with stainless steelend plates secured to a flange found at the end of the cylindricalportion of the tank, for example by bolts engaging through an annularring which overlies the stainless steel end plate in the region of theflange and through the flange to a further annular ring where-upon theyare engageably locatable by means of nuts.

In the case when the apparatus of the present invention is to be used asa water heater, ducts in the form of mains inlet and ring pipes will beconnected to the end plate and the mains water pressurised by a suitablecold water pump. A water pressure safety valve may be provided in theoutlet ring pipe. If the heated water is to be circulated externally ofthe heater a pump may be provided in the ring pipe and the inlet of thering pipe to be located iii the end plate.

In a preferred embodiment of the invention the cylindrical tank is madeof laminated Glass Reinforced Plastics e.g. Fibreglass cloth having oneconvex end and an outwardly directed flange at the other end of the samematerial. A stainless steel end plate is secured by means of bolts tothe flange in sealing engagement therewith and plate may be supportedinside the tank and there should be a clearance between the tubes andthe tank walls to avoid subjection of the latter to excessivetemperatures crisscross reinforcing ribs may be provided on the endplate and a circular flange be provided at right angles to the end platefor supporting the cylinder end and flange.

A pipe is secured to the end plate for the inlet of cold waterpressuried by a cold water pump. A pressure of 32 pound per square inchis required and British Standard Tests would call for a pressure of 48pounds per square inch. It has been found that pressures up to 58 poundsper square inch may be used without failure with a water runningtemperature of F. A thermometer gauge is also located on the end plate.

A gas burner is secured to each of the lower limbs of each of the fourimmersion tubes to give an input of approximately 450,000 B.t.us and arecontrolled by two thermostats, a pressure governor and flame failure andlow pressure cut-outs. Two thermostats are used for reasons of safety.The exhaust ends of the immersion tubes are connected to the end plateand communicate with a flue located on the end plate which is in turnconnected to an exhaust duct or chimney which may be provided withsuitable means for preventing downdraughts. It has been found that themaximum temperature for the heater should be about F. An outlet ringpipe is located in the upper region of the end plate having a pressuresafety valve set at 40 pounds per square inch. A pump is located in thering pipe for circulation of the water and the ring pipe inlet islocated also on the end plate.

At least one pilot light may be provided for each burner. Should onepilot light fail, the supply to the pilot is cut-off and the unit canthen operate at 75% load, which is an important feature where unattendedheaters are operating 24 hours per day. An additional liquid containermay be provided on top of the heater if additional storage of hot-wateris required and a thermal insulation jacket made of polyurethane mayalso be provided.

The present invention will be described further, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a perspective view from one end of a heater showing a portionof the heater cylinder;

FIG. 2 is a longitudinal cross-section of the heater without the burnersand other controls;

FIG. 3 is a section on the line IIIIII of FIG. 2 showing a reinforcingflange and criss-cross stiifeners; and

FIG. 4 is a detail of the heater showing support struts and immersiont-ubes viewed in direction of arrow IV of FIG. 2.

The heater comprises a glass reinforced plastics material cylinder 12,one end of which is convex and the other end open but having a stainlesssteel end plate 13 securable thereto. Legs (not shown) are provided tosupport the cylinder and end plate on any supporting surface upon whichthe heater may be positioned.

Four helically wound U-shaped immersion tubes 14 are locatable withinthe cylinder 12 and provided with a clearance of at least two inchesfrom the lower walls of the cylinder with the aid of support struts 15which rest on cushioned seat 15 which may be of a heat resistantplastics material. The U-shaped tubes 14 extend into the cylinder 12 andthe ends of each pair are separately connected to two flanged apertures16/16, 17/17, 18/ 18' and 19/19 by means of a continuous weld (Argon Arcprocess).

The lower of each pair of apertures i.e. 16, 17, 18 and 19, connected tothe lower limbs of the U-shaped tubes 14, are adapted to receive burners20 provided with known control and safety devices as already mentioned.The burners 20 are fed from mains supply 21. The upper 3 of each pair ofapertures, i.e. 16, 17, 18' and 19', communicate with a flue 22 securedto the end plate 13 and having an exhaust duct or chimney 23. A coldwater inlet 24 is provided in the lower region of the end plate and acold water pump (not shown) may be provided for pressurisation. Anoutlet ring pipe 25 having a pressure safety valve (not shown) isprovided in the upper region of end plate 13 and a pump (not shown) maybe provided in the ring pipe for circulation of the water if desired. Aring pipe inlet 26 is also located on the end pipe and may be suitablyinsulated. A thermometer 27 is also found on the end plate and twothermostats 28 and 28' are provided, for reasons of safety, whichcontrol the burners 20.

The open end of the glass fibre cylinder 12 has an outwardly directedflange 29 formed thereat and bolt receiving apertures 30 radially spacedtherein. Corresponding bolt-receiving apertures 31 are found in theperiphery of the end plate and two mild steel rings 32 and 33, also withcorresponding bolt receiving apertures, are positionable, one 32overlying the end plate 13 and the other, 33, overlying the cylinderflange 29. High tensile bolts 34 hold the end plate 13 and rings 32 and33 securely against the flange 29.

A circular stainless steel reinforcing flange 35, extending into thecylinder 12, is connected at right angles to the end plate andreinforces the cylinder flange and the region thereof. Criss-crossstiflFners 36 are secured to the end plate 13 as additionalreinforcement.

I claim:

1. A liquid heater comprising a .glass fibre cylinder having a closedconvex end and an open end and a stainless steel end plate securable tosaid open end, said end plate having at least one liquid inlet in itslower region and a hot liquid outlet in its upper region and at leastone U-shaped immersion tube adapted to extend into said cylinder andconnected to a combustion product inlet and outlet found substantiallyone below the other respectively in said end plate, said inlet adaptedto receive a burner and said outlet communicating with a flue andexhaust duct, said end plate being securable to said cylinder by meansof bolts engaging through a ring overlying said end plate, through saidend plate, through an outwardly directed flange formed on said open endand through a further ring overlying said outwardly directed flange.

2. A liquid heater according to claim 1 wherein crisscross reinforcingribs are provided on the inward facing side of said end plate and acircular reinforcing flange located in the region of said flange andabutting against the inner surface of said cylinder is provided on saidend plate.

3. A liquid heater according to claim 1 wherein said burner is providedwith safety devices and at least one thermostat is located on said endplate together with a temperature gauge; said hot liquid outletcommunicating with a ring pipe having a circulation pump therein withresidual liquid being returned via said end plate into said cylinder,said hot liquid outlet having a pressure safety device.

References Cited UNITED STATES PATENTS 2,354,932 8/1944 Walker et al122149 XR 2,582,134 1/1952 Kimmell et a1. l22l49 XR 1,939,944 12/1933Barthel et al 122-149 KENNETH W. SPRAGUE, Primary Examiner

